OAS - Osservatorio Astronomico Sormano
	OAS > SAEL - Small Asteroids Encounters List ( Asteroids with H > 22.0 or up to 240 mt in diameter )

Sormano Astronomical Observatory: Small Asteroids Encounters List

Last update: August 19, 2025

Computations by: Francesco Manca,..Piero Sicoli,..Augusto Testa (obs.sormano@alice.it).

Small Asteroids Encounters List

This list includes small asteroids with an Earth MOID (Minimum Orbital Intersection Distance) lower than 0.015 AU. Circumstances of the encounters with our planet are closer in time to the epoch of available observations.
Moreover close approaches to the Earth covering a timespan from 7 to 200 years are calculated as a function of the [U] parameter adopted by the Minor Planet Center, to describe the orbit uncertainty. (For information about the U parameter see MPC 24597 and the related page).

For all the entries Earth-MOID and close approaches (bold-type for distances <= 0.010 AU) are daily recomputed at each MPC orbit update using a software package developed at Sormano Observatory by A. Testa (unpublished, 1993 and 2016) and internal report N.50 (F. Manca, G. Matarazzo and P. Sicoli, 1996).

A similar list for objects of bigger size (H <= 22.0) is available at MBPL (Minor Body Priority List.).

Close encounters within 3 Lunar Distances are summarized at TECA (Table Earth Close Approaches), including the minimum and maximum miss distances in Km.

For related information:

Ephemeris Service:
• Minor Planet Ephemeris Service ( Minor Planet Center )
• Near Earth Objects Dynamics Site ( NeoDyS ) or Mirror Site, NeoDyS at University of Valladolid (Spain)
• Asteroid Observing Services at the Lowell Observatory ( MPC code 699 )
• JPL's HORIZONS System

Close Encounters and Selected Objects lists:

• Table of Asteroids Next Closest Approaches to the Earth ( TECA )
• Table of Asteroids Next Closest Approaches to the Moon ( TAM )
• List of selected objects ( MBPL - Minor Body Priority List ), H <= 22.0
• List of Planetary Close Encounters ( PCEL - with planets Mercury, Venus and Mars)
• List of Cometary Close Encounters ( CCEL - with planets Mercury, Venus, Earth and Mars )
• List of Closest approaches to the Earth at the Minor Planet Center
• NEO Earth Close-Approach Tables at the Jet Propulsion Laboratory ( JPL )
• Spaceguard Central Node ( SCN )
• UAI-Unione Astrofili Italiani Minor Planets Section
• Near-Earth Object Human Space Flight Accessible Targets Study (NHATS)
• ESA - NEO Coordination Centre

Virtual Impactor:

• JPL Sentry System (SENTRY Current Impact Risks)
• NeoDys Risk page (CLOMON2 System)

Hazard Scale:

• Torino Impact Hazard Scale
• Palermo Technical Impact Hazard Scale

The following service, courtesy of the Minor Planet Center , is intended as support and in addition to the objects available in the SAEL list for which follow-up or recovery is needed. The service will return all objects (NEOs and Comets) based on criteria specified by the user and NOT filtered in relation to their MOID value. Astrometric observations of any of the following objects should be sent directly to obs@cfa.harvard.edu.